Aging of Skin
skin as a role model for aging and cancer
The skin is a good role model for aging and for cancer. Aging of the skin is almost wholly photolytic, as may be seen by looking at the skin of the aged. Facial skin on the elderly is usually badly wrinkled and damaged. On the other hand, skin on parts of the body that haven't been exposed much to sunlight is juvenile. The chance of cancer arises steadily with exposure. (Tanning is just what the word suggests: stiffening the skin into leather.) This runs counter to the cosmetic goals of our society, which places a premium upon getting a tan.
Do other tissues age in the same way?
Presumably, the same thing happens with other tissues exposed to carcinogens and other environmental insults. They age in the same way as skin, but they're not as easily observed and assessed. This suggests that if environmental assaults could be minimized, the body might last proportionately longer. (Grated: there is a Hayflick limit that will eventually bring down the system, but organisms usually die well before the limit is reached.)
Different tissues age at different rates
Clearly, different tissues age at different rates, depending upon the environmental challenges to which they are exposed. An individual dies when one or more subsystems break down. Unfortunately, it's the cumulative effects that count, and there's little warning of this until it's too late.
We need to know the suspected relationships between what we do and our rates of aging/cancer incubation
This suggests that cancer prevention and aging retardation should begin at an early age. Unfortunately, the medical community has been unable to properly pitch this to the public. Part of the reason may be the fact that the medical community must be very conservative in making any claims. It can take 20 to 30 years to get adequate agreement upon medical recommendations to publish them officially. However, people need to be aware of the relationship between aging, and cancer, and of the risk factors that are suspected, as well as the risks that have been proven. It would make sense to provide an early education to the young in such health preservation measures. For example, there are studies showing the interrelationship between high levels of vitamin D and protection against breast cancer. This is not yet established beyond a doubt, so the National Cancer Institute isn't recommending that anyone take vitamin D supplements--yet. Calcium has been shown to lower serum levels of vitamin D by potentiating the elimination of vitamin D from the body, and thus, raising the risk of hormone-dependent cancers. Calcium has also been implicated in arterial plaques formation. On the other hand, we need calcium for strong bones, and for protection against osteoporosis. Calcium is generally given with vitamin D to aid in calcium absorption.